The effect of local atomic interactions upon step bunching and de-bunching, upon vicinal face-centered cubic (111) surfaces which were inclined in the [¯211] direction, was modelled by employing kinetic Monte Carlo simulations under annealing conditions. Various local interactions gave rise to characteristic step-bunching configurations. By using transition probabilities which described local atomic interactions, in which both the initial and final numbers of atomic bonds were involved in the surface diffusion process (and strongly enhanced surface diffusion also occurred along the close-packed <01¯1> step edges), a quasi-equilibrium configuration which consisted of large (100) and (111) terraces evolved. On the other hand, for a system with strongly enhanced surface diffusion along the <01¯1> step edges (but with locally isotropic diffusion in all other directions), where only the initial number of atomic bonds before a hop was considered, a quasi-equilibrium surface configuration was formed. The step-bunching here involved alternating (021) and (012) facets which were surrounded by large (111) terraces. Strongly enhanced surface diffusion along <01¯1> step edges was also shown to be necessary for the stability of step bunches in this system. It was shown that the step-bunching could be completely quenched, for compact steps, due to an increased step-edge barrier to mass transport across the <01¯1> step edges. It was shown that step-bunching could not occur without mass transport occurring between adjacent terraces.

M.I.Larsson: Physical Review B, 1997, 56[23], 15157-66